A doha is a couplet consisting of two lines, each of 24 instants (Matras). The rules for distinguishing light and heavy syllables is slightly different from Sanskrit. Each line has 13 instants in first part and 11 instants in the second. The first and third quarters of doha have 13 instants which must parse as 6-4-3.
Many Hindi poets have created several books which explain whole stories and epics in the form of dohas. The most popular is Tulsidas' Ramcharitmanas, a popular rendition of the Sanskrit epic Ramayana.
निन्द(३)क निय(३) रे (२) राखि(३)ए(२) आँगन (४) कुटी छ(४) वाय(३)==> 13/11
बिनु पा(४)नी सा(४) बुन बि(३) ना(२) निर्मल (४) करे सु(४) भाय(३)==> 13/11
[Parenthesized numbers indicate mAtraa-counts.] Here is a Doha by Rahim:
जो रहीम उत्तम प्रकृति का कर सकत कुसंग |
चन्दन विष व्यापत नहीं लिपटे रहत भुजंग ||
Says Rahim, one who is of inherently noble nature, will remain unaffected even when he associates with bad people.
The sandalwood plant does not absorb poison when the snakes wind around it.